The Warriors have won seven on the spin to climb into third in the table but the battle in the top seven remains very tight with three rounds to go.
Defeat to Scarlets - who currently sit fourth and have already beaten the Scottish side in the league this year - would put their play-off hopes back in jeopardy.
But by that same token a victory could put the defending champions in with a strong shout of a home-playoff berth - so small are the margins are the top.
"We've got three tough games left to play of the regular season, starting with Scarlets tomorrow afternoon," said Townsend.
"They've already beaten us this season and they're only three points behind us in the league, so we're well aware of the challenge we face.
"The squad have trained really well this week and we welcome back Stuart Hogg and Josh Strauss to the squad following our win over Zebre last weekend."
Stuart Hogg, Josh Strauss and Lee Jones return to the starting XV following the win over Zebre in Parma last Friday.
Scotland full-back Hogg starts at 15, while Jones is named on the left wing. On the opposite flank is Tommy Seymour who played in Glasgow's last match against the Scarlets, when they won 9-6 in the European Rugby Champions Cup last December.
Mark Bennett and Alex Dunbar renew their centre partnership, while Finn Russell and Henry Pyrgos are the half-back paring.
Gordon Reid, Fraser Brown and Sila Puafisi pack down in the front-row. Tim Swinson and captain Jonny Gray are the two locks, while Rob Harley, Ryan Wilson and Strauss make up the back-row.
Amongst the replacements is Taqele Naiyaravoro, who scored three tries against the Scarlets on their most recent visit to Scotstoun in December.
Scarlets tripped up at home to Cardiff Blues in round 19 and have not lost successive Guinness PRO12 matches at Parc y Scarlets since the start of the 2013/14 campaign.
The two sides have met on three occasion this season with Scarlets winning 16-10 at Scotstoun in September and Warriors taking both encounters in the Champions Cup in December.
Head coach Wayne Pivac has named a strong side to take on the defending champions at the Parc with players making a return from long-term injuries for the all-important game.
International full-back Liam Williams has been named in the starting XV in what will be only his second game of the season for the Scarlets, previously playing 60 minutes against Connacht at the Sportsground in January.
Steve Shingler will join him in the starting XV having made a return from knee injury and has been given the nod to start in the ten jersey.
Looking ahead to Saturday afternoon's game Pivac said: "We have a lot of respect for Gregor Townsend and his side. They're the form team at the moment. They've won a run of games but they're also putting teams away and scoring tries.
"I think we have to make sure that defensively we're up to the challenge and line speed will play its part.
"They're looking like definite contenders and top-four material. It's going to be a big challenge but we owe our crowd and we owe ourselves a big performance after our last outing."
At Parc y Scarlets 3.15pm Live on Sky Sports
Referee: George Clancy (80th competition game)
Assistant Referees: Ian Davies, Simon Brickell (both WRU)
Citing Commissioner: Dennis Jones (WRU)
TMO: Jon Mason (WRU)
Scarlets
10 - 46
HT: 10 - 20
Glasgow Warriors
16th April 2016
15:15
Parc y Scarlets
8165
GUINNESS PRO12
Referee: George Clancy